Abrasive.



UNITED STATES PATENT OFFICE.

FREDERICK M. BECKET, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO ELECTRO METALLURGICAL COMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF NEW YORK.

Patented Sept. 24, 1918.

ABRABIVE.

1,279,828. Specification of Letters Patent.

No Drawing. Application flied April 10, 1916. Serial No. 90,209.

To all whom it may concern:

Be it known that 1, FREDERICK M. Bncnn'r, a subject of the King of England, residing at Niagara Falls, in the county of Niagara and State of New York, have invented certain new and useful Improvements in Abras ives, of which the following is a specificat1on.

This invention relates to an abrasive substance containing as essential components iron, chromium, carbon and usually silicon, and distinguished from the heretofore known ferrochrome alloys by its composition, and by the possession to a very high degree of the combined qualities of toughness, hardness, and resistance to oxidation both at low and high temperatures, In respect to this combination of qualities, the new alloy is superior to manganese steel. The alloy possesses other valuable characteristics as men-- tioned below.

An alloy combining toughness, hardness and resistance to oxidation to a remarkable degree contains- Chromium 25 -3O Carbon 1.5 a Silicon 0.0- 3 Iron 73 -63.5% usual] with traces of manganese, sulfur,

phosp orus, copper, and perhaps other elements.

To a lesser although still marked degree, this combination of qualities is found in alloys outside of the range above indicated; For example, alloys containing as low as 18 per cent. and as high as 35 per cent. of chromium, the carbon and silicon being approximately as specified above, are servlceable for abrasive purposes as mentioned below.

The extreme toughness and hardness of the above-mentioned alloys render them highly eflicient and desirable substitutes for chilled shot and crushed steel in the cutting and grinding of marble, granite and the like; and moreover, their freedom from tendency to oxidize or rust in presence of water resents the advantage that there is no liabi ity to staining the stone. For instance, it is well known that crushed steel cannot be used for marblerinding where freedom from staining is o importance; whereas the present alloys are eminently suited for this use, in addition to being capable of much more rapid cutting or grinding. The degree of limits a tendency to brittleness is observed.

As an illustration of resistance to oxida-- tion at high temperatures, a cast bar of alloy containing chromium 28%, carbon 2.72%, silicon 0.40%, the balance practically all iron, was exposed continuously at 1100 C. for two weeks to an oxidizing atmosphere in an electrically heated muflle furnace without undergoing appreciable oxidation, whereas a mild steel under identical conditions was uickly converted into scale oxid.

Al oys within the limits above specified possess a strongly marked fibrous structure. They can be forged and machined, although with difliculty as compared with ordinary steel. They can be annealed and also tempered, and in general are responsive to heat treatment, although to a materially less degree than ordinary high-carbon steels.

Among the uses to which the possession of the above-mentioned roperties render the new alloys particularly adapted are mentioned the following (1) As an abrasive: For example the molten alloy may be poured into water in order to granulate it, and the resulting granules crushed by stamping or otherwise, and graded, thereby producing irregularly shaped cutting grains or particles of approximately umform size. The abrasive particles may be used as substitutes for chilled shot or crushed steel in the grinding and cutting of marble and ranite as mentioned above, or they may e bonded by a silicate or other bond into abrasive wheels or other implements, the firing being carried out under ordinary conditions in case a silicate bond is used.

(2) As a non-slipping surface in conjunction with cements, artificial stone compositions or the like.

The hereindescribed alloys may be prepared byvarious methods, as for example y melting commercial grades of h gh-carbon ferrochrominm with the requisite proportion of steel scrap in a crucible furnace, adding if necessarv silicon or ferrosihcon. The composition of the component materials being known, the proportions of such materials required to produce an alloy of any desired composition is easily computed arithmetically.

I claim:- 1. An abrasive material in the form of larly shaped grains of approximately uni orm size, and containing chromium 18 to 35 per cent., carbon 1.5 to 3 per cent. and

silicon u to three per cent., the ba ance principal y iron. 10 2. An abrasive material in the form of irregularly shaped grains of approximately uni orm size, and containing chromium 25 to 30 per cent, carbon 1.5 to 3 per cent., and silicon u to three per 15 principa y iron.

cent, the balance 3. An abrasive wheel or other implement containing bonded grains of an alloy consisting essentiall of iron, chromium an carbon in about t e proportions 4. An abrasive wheel or other 1m lament 20 containing bonded sins of an al 0y consisting essentially 0 iron, chromium, carbonnnd silicon in about the proportions spec1fied.

In testimo whereof I afiix my signature 25 in presence 0 two witnesses.

FREDERICK M. BEGKET. Witnesses:

Mm! Son's, SIDNEY CERTIFICATE OF CORRECTION;

Patent No. 1,279,828. Granted September 24, 1918, to

FREDERICK II. BECKET.

lt ia hereby certified that the State of incorporation oi the aeaignee in the above nnlitered patent waa erroneollaly liven aa "New York whereas aaid State ahnnid have been given an "Ieat Virginia", at than by the records of aaaigaeat: in thin office: and that the aaid Letters Patent ahenid he read with thia correction therein that the ante my conform to the record of the eaae In the Patut Office.

Signed and healed thia 19th day of August, A. D. 4927.

ll. 1. Moore. Seal. Aetln Gonnniaaloner o! Patea'ta. 

